Music transposition devices are known. Some, such as those disclosed in New Zealand patent specification 168417 and U.S. Pat. Nos. 5,804,460 and 3,791,254, employ a slide rule type arrangement. However students are easily confused and intimidated by a complex array of letters and symbols. Such known devices also suffer from the fact that the student must already possess quite detailed knowledge of music theory to be able to use them effectively.
Another form of music transposition is disclosed in U.S. Pat. No. 4,134,326. The device disclosed in that specification has a number of angular rings that are rotatably mounted on an axle. The names of notes are printed on the peripheral surface of each ring so that when the rings are appropriately aligned, musical relationships can be determined. The primary purpose of the prior art device is however to assist in the transposition of chords. To use the device, the key or tonic note for a particular chord is selected on the first or left hand ring and then each successive ring is aligned with the other notes of the chord. Having done that, the rings can be locked in place and the rings rotated together so that the corresponding type of chord of another key can be read of the device with the assistance of a moveable viewing screen. Modification indicators can be rested onto part of the viewing screen to emphasise those parts of the chord that characterise the particular type of chord eg minor, seventh, augmented etc.
U.S. Pat. No. 4,961,362, disclosed a disk type of calculator assembly which will assist in the calculation of chords and keys and uses a colour chart to assist in defining a conversion scale for roots and inversions.
Patent specification GB 2119154B discloses a musical scale indicator which has eight overlapping circles to display musical scales in twelve keys. The rear surface of the circles displays numbers which when correctly registered with a window sill enable the front of the indicator to display the notes of the chosen scale.
U.S. Pat. No. 3,002,435 discloses a music transposition device which is cylindrical and which carries indicia to represent notes of the chromatic scale. The device has a knob at one end which displays twelve key signature designations. A cylindrical member formed of transparent material to overly the first cylinder is joined to a knob at the other end of the cylinder and displays a series a chord designations.
Disadvantages of the above know devices is that a person must have sufficient knowledge of music theory to be able to utilize the device which are generally cumbersome to hold and difficult to understand and use.
It is the object of this invention to provide a music teaching aid which represents an improvement over known music teaching aids and known music transposition devices in terms of being easy to be used by students with limited knowledge of music theory, and which is versatile and attractive in appearance.
It is a further object of the invention to provide a music teaching aid which employs a specific form or forms of colour coding to assist in the identification and the correlation between musical notes.
It is a yet further object of the invention to provide an optional feature whereby the music teaching aid may include a facility to produce an audible repetitive frequency to enable the music teaching aid to also act as a metronome.